Abstract

New methods to reduce the total sulphur content of coals are being developed since the introduction of legislation requiring cuts in sulphur emissions to the atmosphere. It is known that weakly paramagnetic pyrite (FeS₂) particles are difficult to remove from clean coal by standard magnetic separation techniques. Data is presented here comparing standard magnetic separation tests to results achieved when the coal is subjected to a caustic microwave leach pretreatment, prior to conventional dry magnetic separation. A significant increase in the removal of total sulphur is observed when this pretreatment is applied to the coal.